Electronic cigarettes, also called e-cigarettes or electronic nicotine delivery systems (ENDS) are battery- operated devices that deliver nicotine and other chemicals to users in vapor instead of smoke. Since their introduction into the market in 2004, ENDS have gained popularity around the world. In the US, in 2009, ENDS were still quite rare. However, by 2014 it was estimated about 13% of US adults had tried ENDS, with use differing by age, sex, and race and Hispanic or Latino ethnicity. Because using ENDS does not involve the combustion of chemicals found in cigarettes, some have speculated that ENDS use is safer than cigarette smoking. However, evidence on the health effects of ENDS is lacking, especially given the unknown effects the aerosols and flavorings in ENDS liquids. There is no existing study focusing on the effects of ENDS use on cardiovascular (CVD) and other health risks in a minority population. The over-arching goal of this proposal is to explore and generate hypotheses on associations of using ENDS and CVD and other health risks in Hispanics/Latinos?in an efficient and highly cost-effective manner. By taking advantage of existing data from a large community-based sample of more than 12,000 persons of Hispanic/ Latino origin, men and women, ages 18-74 at baseline (2008-2011) from The Hispanic Community Health Study / Study of Latinos (HCHS/SOL) who participated in both HCHS/SOL baseline and follow-up (2015-17) examinations we are to address the following Specific Aims: 1) Determine the prevalence of ENDS use in Hispanics/Latinos in the population-based HCHS/SOL Visit-2 dataset, and to assess demographic, socio-economic, and cultural factors associated with ENDS use at Visit-2. 2) Explore and generate hypotheses on cross-sectional associations of ENDS use with levels of CVD risk factors, other health measures, assessments of subclinical atherosclerosis, and markers of inflammation, including heart rate, blood pressure, high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides, fasting glucose, BMI, and WBC at Visit-2, taking into account history and current use of tobacco products. 3) Explore and generate hypotheses on associations of ENDS use retrospectively from Visit-2 with changes from Visit-1 to Visit-2 in levels of CVD risk factors, other health measures, and markers of inflammation (as listed above in aim 2), again taking into account history and current use of tobacco products. We make the assumption that baseline data were obtained prior to first ENDS use due to the timing of Visit-1, i.e., due to the novelty of ENDS at the baseline exam in 2008-2011, use of ENDS, although unmeasured, is essentially zero at baseline. This assumption will be validated with use of newly acquired data from a HCHS/AOL sub-cohort in the next aim. 4) Obtain new data to examine the use of ENDS in Hispanics/Latinos as it relates to motivations, dose, flavors, and duration by mailing a questionnaire to ENDS users who participated in Visit-2 at the Chicago HCHS/SOL Field Center.